With numerous emerging internet of things (IoT) devices, they generate big data. The big data transmitted to the cloud or fog will consume massive network bandwidth. This may result in the IoT network easily encountering network congestion. Moreover, there are IoT applications that need to transfer multimedia data with multiple quality of service (QoS) requirements. A state-of-the-art, MINA, intends to meet multiple QoS requirements of IoT applications; however, it is unable to guarantee QoS requirements of high-priority IoT applications and it is also unable to adapt to the current network status. To conquer the above problems, we propose an application-aware QoS routing algorithm (AQRA) for SDN-based IoT networking to guarantee multiple QoS requirements of high-priority IoT applications and to adapt to the current network status for better routing paths. Evaluation results have shown that, the AQRA has better fitness ratios of QoS requirements compared to MINA while multiple QoS requirements of high-priority IoT applications are guaranteed. The AQRA improves the average end-to-end flow performance by 10.75%, 11.88% and 10.82% compared to MINA in terms of delay, jitter and packet loss rate, respectively. The AQRA improves the standard deviation of end-to-end flow performance by 14.37%, 17.95% and 14.28% compared to MINA in terms of delay, jitter and packet loss rate, respectively. In addition, the runtime of the AQRA is 38.56% shorter than that of MINA.